Installation of cured in place liners with air and steam and installation apparatus

ABSTRACT

A process for lining an existing pipeline or conduit with a flexible resin impregnated cured in place liner by pulling in the liner and inflating an eversion bladder with air and curing the liner with flow-through steam without loss of pressure is provided. The liner includes a resin absorbent material in tubular form with an impermeable membrane forming an outer layer. The absorbent material is saturated with a thermoset resin and pulled into the existing conduit. A flexible inflation bladder is passed through a gland mounted on an eversion apparatus and everted into the collapsed liner. The gland is pressurized to isolate the eversion bladder. As the bladder reaches the distal manhole, it enters a receiving canister where it is punctured while maintaining air pressure within the bladder. Steam is then introduced into the bladder to cure the resin and is exhausted through the receiving canister. The bladder is then removed and lateral service reinstated.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a method for installation of a cured inplace liner into an existing conduit by pulling in and inflating theliner and more particularly to a method of trenchless rehabilitation ofan existing conduit by pulling into the existing conduit a resinimpregnated liner, everting an inflation bladder into the liner with airand curing the resin with continuous flow-through steam without loss ofpressure in the bladder and to the apparatuses for practicing themethod.

[0002] It is generally well known that conduits or pipelines,particularly underground pipes, such as sanitary sewer pipes, stormsewer pipes, water lines and gas lines that are employed for conductingfluids frequently require repair due to fluid leakage. The leakage maybe inward from the environment into the interior or conducting portionof the pipelines. Alternatively, the leakage may be outward from theconducting portion of the pipeline into the surrounding environment. Ineither case, it is desirable to avoid this leakage.

[0003] The leakage may be due to improper installation of the originalpipe, or deterioration of the pipe itself due to normal aging or to theeffects of conveying corrosive or abrasive material. Cracks at or nearpipe joints may be due to environmental conditions such as earthquakesor the movement of large vehicles on the overhead surface or similarnatural or man made vibrations, or other such causes. Regardless of thecause, such leakages are undesirable and may result in waste of thefluid being conveyed within the pipeline, or result in damage to thesurrounding environment and possible creation of a dangerous publichealth hazard. If the leakage continues it can lead to structuralfailure of the existing conduit due to loss of soil and side support ofthe conduit.

[0004] Because of ever increasing labor and machinery costs, it isincreasingly more difficult and less economical to repair undergroundpipes or portions that may be leaking by digging up and replacing thepipes. As a result, various methods had been devised for the in placerepair or rehabilitation of existing pipelines. These new methods avoidthe expense and hazard associated with digging up and replacing thepipes or pipe sections, as well as the significant inconvenience to thepublic. One of the most successful pipeline repair or trenchlessrehabilitation processes that is currently in wide use is called theInsituform® Process. This Process is described in U.S. Pat. Nos.4,009,063, 4,064,211 and 4,135,958, the contents of all of which areincorporated herein by reference.

[0005] In the standard practice of the Insituform Process an elongatedflexible tubular liner of a felt fabric, foam or similar resinimpregnable material with an outer impermeable coating that has beenimpregnated with a thermosetting curable resin is installed within theexisting pipeline. Generally, the liner is installed utilizing aneversion process, as described in the later two identified Insituformpatents. In the eversion process, radial pressure applied to theinterior of an everted liner presses it against and into engagement withthe inner surface of the pipeline. However, the Insituform Process isalso practiced by pulling a resin impregnated liner into the conduit bya rope or cable and using a separate fluid impermeable inflation bladderor tube that is everted within the liner to cause the liner to cureagainst the inner wall of the existing pipeline. Such resin impregnatedliners are generally referred to as “cured-in-place-pipes” or “CIPPliners” and the installation is referred to a CIPP installation.

[0006] The CIPP flexible tubular liners have an outer smooth layer ofrelatively flexible, substantially impermeable polymer coating theoutside of the liner in its initial state. When everted, thisimpermeable layer ends up on the inside of the liner after the liner iseverted during installation. As the flexible liner is installed in placewithin the pipeline, the pipeline is pressurized from within, preferablyutilizing an eversion fluid, such as water or air to force the linerradially outwardly to engage and conform to the interior surface of theexisting pipeline. Cure is initiated by introduction of hot water intothe everted liner through a recirculation hose attached to the end ofthe everting liner. The resin impregnated into the impregnable materialis then cured to form a hard, tight fitting rigid pipe lining within theexisting pipeline. The new liner effectively seals any cracks andrepairs any pipe section or pipe joint deterioration in order to preventfurther leakage either into or out of the existing pipeline. The curedresin also serves to strengthen the existing pipeline wall so as toprovide added structural support for the surrounding environment.

[0007] When tubular cured in place liners are installed by the pull inand inflate method, the liner is impregnated with resin in the samemanner as the eversion process and positioned within the existingpipeline in a collapsed state. A downtube, inflation pipe or conduithaving an elbow at the lower end typically is positioned within anexisting manhole or access point and an everting bladder is passedthrough the downtube, opened up and cuffed back over the mouth of thehorizontal portion of the elbow. The collapsed liner within the existingconduit is then positioned over and secured to the cuffed back end ofthe inflation bladder. An everting fluid, such as water, is then fedinto the downtube and the water pressure causes the inflation bladder topush out of the horizontal portion of the elbow and cause the collapsedliner to expand against the interior surface of the existing conduit.The eversion of the inflation bladder continues until the bladderreaches and extends into the down stream manhole or second access point.At this time the liner pressed against the interior surface of theexisting conduit is allow to cure. Cure is initiated by introduction ofhot water into the inflation bladder which is circulated to cause theresin in the impregnated liner to cure.

[0008] After the resin in the liner cures, the inflation bladder may beremoved or left in place in the cured liner. If the inflation bladder isto be left in place, the bladder will generally be one that has arelatively thin resin impregnable layer on the inside of the impermeableouter layer. In this case, the impregnable layer after eversion willcause the bladder to adhere to the resin impregnated layer of the lineras is well known in the art. At this time, entry into the manhole oraccess point is required to open the liner to release the water used toinflate the bladder and to cut off the ends extending into the manholes.When the inflation bladder is to be removed, it may be removed bypulling at the evasion end on a holdback rope attached to the trailingend of the inflation bladder used to control the speed of the eversion.This is generally done after puncturing the bladder at the receiving endto release the water used to evert the bladder and initiate the resincure. Finally, the downtube can then be removed and service can bereconnected through the lined pipeline. If intersecting serviceconnections are present, they would be reopened prior to resumption ofservice through the lined pipeline.

[0009] When a cured in place liner is installed using the pull in andinflate method, the outer impermeable layer of the liner remains pressedagainst the interior surface of the existing conduit. Certain advantagesmay be attained by this method of installation because the resin in theresin impregnable layer of the liner is trapped between two impermeablelayers, namely the outer coating of the liner and the inflation bladderon the inside. Accordingly, there is little or no resin migration out ofthe liner. In a pull in and inflate installation, the liner coating neednot be as strong as required in an installation by eversion, because thecoating is not subjected to the pressure head required to evert theliner using the eversion process. Additionally, the coating does notcome into contact with hot fluid circulating during the resin curecycle. Thus, the liner may be of more uniform thickness in a pull in andinflate using an inflation bladder cured in place process compared towhen the liner itself is everted.

[0010] While the pull in and inflate method has these advantages, theinstallation process is somewhat more complex than an eversion. Pull inand inflate requires banding the inflation bladder to the downtube elbowand securing the collapsed liner already positioned in the existingpipeline to the downtube. This requires work within a restricted manholespace. Additionally, at the end of the installation, the inflationbladder may need to be removed after being cut at the distal end torelease the water used as the inflation fluid.

[0011] While the pull in and inflate method utilizing water does havethe various advantages noted above, the shortcomings tend to increaselabor costs which are a significant aspect of the installation process.Accordingly, it is desirable to provide a rehabilitation method usingpull in and inflate, wherein the liner is inflated with air and theresin is cured by steam flow-through, to take advantage of the energyavailable in the steam to provide an installation method which is fasterand more efficient economically than various rehabilitation methodscurrently practiced.

SUMMARY OF THE INVENTION

[0012] Generally speaking, in accordance with the invention, a method ofrehabilitation of an existing pipeline by pull in and inflateinstallation of cured in place liners using air to inflate an inflationbladder and curing with flow-through steam without loss of pressure inthe liner is provided. A resin impregnated liner is pulled into theexisting pipeline to be repaired and cut at the ends to extend into bothmanholes. An inflation bladder in a length somewhat longer than thepipeline to be lined is attached to an inflation elbow that is placed inthe upstream or eversion manhole and the collapsed liner is secured tothe outlet end of the bladder on the elbow. The elbow includes a glandat the inlet side through which the bladder passes and which can bepressurized to seal against the bladder during inflation. The bladder iseverted using air causing the liner to expand progressively. When thebladder approaches the downstream access point, the bladder isrestrained and clamped at the gland on the inlet side of the eversionelbow. The bladder is then allowed to evert further into a receivingcanister in the downstream or receiving manhole and punctured. Airpressure is maintained in the bladder and exits the canister through anexhaust line attached to the distal end of the canister.

[0013] While maintaining pressure in the bladder, steam is introducedinto the elbow downstream of the gland and passes into the bladder toinitiate the cure and exit through the canister exhaust. After the resinin the liner is cured, the steam is turned off and the air pressure isadjusted to maintain pressure in the bladder and maximize cooling. Theinflation bladder is then withdrawn by de-everting using a power spoolat the eversion end. Any condensate in the bladder is removed through acondensate trap in the elbow in the eversion manhole.

[0014] In a preferred embodiment of the invention, an easement vehiclecarries a spooled inflation bladder of appropriate length on a stagingspool to the upstream access and includes valves and regulators forapplying pressurized air for eversion of the bladder and steam forcuring of the liner and removal of the bladder after cure. In a mostpreferred aspect of the invention, the inflation fluid is air which isintroduced into the inflation bladder at an elbow having an inlet glandthrough which the liner passes. After the bladder inflates the liner, itenters a receiving canister having a puncturing element positioned inthe downstream manhole. The bladder is sealed against the canister walland is punctured to allow air to exit through an exhaust. Steam isintroduced at the elbow downstream of the gland pressurized against thebladder. Steam flows through the bladder to cure the resin quickly andcompletely without loss of pressure in the bladder.

[0015] Accordingly, it is the object of the invention to provide animproved method for rehabilitation of an existing pipeline by theinstallation of a cured in place liner by the pull in and inflate methodutilizing air to evert an inflation bladder.

[0016] Another object of the invention is to provide an improved methodfor pull in and inflate installation of a cured in place liner byutilizing flow-through steam to effect cure of the resin.

[0017] A further object of the invention is to provide an improvedmethod of installation of a cured in place liner by pull in and inflatewherein air is used to evert the bladder to inflate the liner andflow-through steam is used to cure the resin of the bladder which isautomatically punctured when the bladder enters a receiving canister inthe downstream manhole.

[0018] Still another object of the invention is to provide a receivingcanister to puncture automatically the inflation bladder and allow forregulation of air and steam flowing through the inflation bladder.

[0019] Still another object of the invention is to provide an improvedeasement unit for use in the installation of cured in place liner by thepull in and inflate method including a staging reel for holding thelength of inflation bladder to be used.

[0020] Yet another object of the invention is to provide an installationelbow including a sealing gland to permit introduction of air into theinflation bladder for everting the installation bladder and expandingthe liner and steam for curing.

[0021] Still another object of the invention is to provide a manifold toregulate air and steam to be fed to an eversion elbow to effect aireversion of an inflation bladder and flow-through steam for curing.

[0022] Still other objects and advantages of the invention will in partbe obvious and will in part be apparent from the specification.

[0023] The invention accordingly comprises the several steps and therelation of one or more of such steps with respect to the others, andthe apparatuses possessing the features, properties and relation ofelements which are exemplified in the detailed disclosure and the scopeof the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] For a fuller understanding of the invention, references had tothe following description taken in connection with the accompanyingdrawings in which:

[0025]FIG. 1 is a perspective view of a length of a typical resinimpregnable cured in place liner suitable for use in lining an existingpipeline in accordance with the invention;

[0026]FIG. 2 is a perspective view of the liner of FIG. 1 with theleading end folded with a cable secured to it for pulling the liner intothe existing pipeline;

[0027]FIG. 3 is a cross-sectional elevational schematic view showingpulling in of a resin impregnated cured in place liner of the typeillustrated in FIGS. 1 and 2 from a downstream or receiving manhole toan upstream or eversion manhole at the start of the installation processto line an underground conduit;

[0028]FIG. 4 is a cross-sectional elevational schematic view of thecollapsed cured in place liner of FIG. 3 after it is positioned withinthe existing conduit at the start of the installation in accordance withthe invention;

[0029]FIG. 5 is an elevational view of an eversion apparatus constructedand arranged in accordance with the invention with the eversion bladderand starter sleeve installed;

[0030]FIG. 6 is a cross-sectional elevational view showing the downtubeand elbow assembly of FIG. 5 inserted into the liner at the start of theeversion in accordance with the invention;

[0031]FIG. 7 is a detailed sketch of the air and steam piping andeversion apparatus in the eversion manhole during an installation;

[0032]FIG. 8 is a detailed schematic view of the manifold forcontrolling air and steam temperature and volume in the process;

[0033]FIG. 9 is a cross-sectional elevation view of the reviewingcanister constructed and arranged in accordance with a preferredembodiment of the invention positioned in the receiving manhole beforecompletion of eversion of the bladder; and

[0034]FIG. 10 is a cross-sectional elevational view of a receivingcanister in the receiving manhole as used in accordance with analternative embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035]FIG. 1 illustrates a flexible cured in place liner 11 of the typegenerally well known in the art. Liner 11 is formed from at least onelayer of a flexible resin impregnable material, such as a felt layer 12having an outer impermeable polymer film layer 13. Felt layer 12 andfilm layer 13 are stitched along a seam line 14 to form a tubular liner.A compatible thermoplastic film in a form of a tape or extruded material16 is placed on or extruded over seam line 14 in order to ensure theimpermeability of liner 11. In the embodiment illustrated in FIG. 1 andused throughout this description, liner 11 includes an inner second feltlayer 17 also stitched along a seam line 18 which is positioned at apoint in the tube other than the location of seam line 14 in outer feltlayer 12. Liner 11 has a leading end 19 with a continuous length storedin a refrigeration unit 21 (FIG. 3) to suppress early cure of the resin.Liner 11 is cut to a desired length after being pulled into the existingpipeline.

[0036] Liner 11 of the type illustrated in FIGS. 1 and 2 is impermeableto water and air. This will allow use in an air or water eversion asdescribed above. However, in a pull in and inflate installation inaccordance with the invention, the liner need only be sufficientlyimpermeable to allow for suitable wet out and retention of resin and toprevent damage to the liner as it is pulled into the existing pipeline.

[0037] For larger liner diameters, several layers of felt material maybe used. Felt layers 12 and 17 may be natural or synthetic flexibleresin absorbable material, such as polyester or acrylic fibers.Impermeable film 13 in outer layer 12 may be a polyolefin, such aspolyethylene or polypropylene, a vinyl polymer, such as polyvinylchloride, or a polyurethane as is well known in the art. In the initialstep in all trenchless rehabilitation installations, the existingpipeline is prepared by cleaning and videotaping.

[0038] Prior to commencing installation pursuant to the method inaccordance with the invention, a curable thermosetting resin isimpregnated into the felt of a liner 33 similar to liner 11 by a processreferred to as “wet-out”. The wet-out process generally involvesinjecting resin into felt layer or layers 12 and 17 of liner 11 throughthe end or an opening formed in impermeable film layer 13, drawing avacuum and passing the impregnated liner through nip rollers as is wellknown in the lining art. One such procedure of this vacuum impregnationis described in Insituform U.S. Pat. No. 4,366,012, the contents ofwhich are incorporated herein by reference. A wide variety of resins maybe used, such as polyester, vinyl esters, epoxy resins and the like,which may be modified as desired. It is preferable to utilize a resinwhich is relatively stable at room temperature, but which cures readilywhen heated.

[0039]FIG. 2 shows a leading end 32 of a liner 33 with a winch rope orcable 22 secured by a slip knot and three half hitches 23 for pullingliner 33 into the pipeline. Leading end 32 of liner 33 and cable 22 maybe duct taped to prevent slip of cable 22 and to seal leading end 32.

[0040] Referring now to FIG. 3, an existing pipeline 24 located below asurface 25 with a section 26 in need of repair between an upstreamopening 27 and a downstream opening 28. Pipeline section 26 has aplurality of cracks 29 and a section of missing pipe material 31. Thereis first upstream or access at an upstream manhole U and a seconddownstream access opening at manhole D. Of course, the installation andsteps to be described can be done at either end of pipeline section 26to be repaired. For convenience, the process in accordance with theinvention will be described with the eversion proceeding from upstreammanhole U to downstream manhole D.

[0041] A conventional jetter is used to pull in winch cable 22 intopipeline section 26 from upstream manhole U to downstream manhole D.Cable 22 is then connected to leading end 32 of liner 33. Liner 33 is ofthe type shown in FIG. 1, but may have a less robust impermeable filmthan used in eversion installations. Liner 33 is pulled fromrefrigeration unit 21 positioned at downstream manhole D into pipelinesection 26 to be repaired by a winch 34 positioned on an easement unit36 on surface 25 at upstream manhole U.

[0042] Winch 34 may be a stand alone unit positioned on surface 25, orbe mounted on a vehicle, such as easement unit 36. Easement unit 36includes additional apparatuses such as a bladder staging reel 37including a length of an inflation bladder 38 of a length a safe marginlonger than the length of pipeline section 26 to be repaired. Typically,an excess of about 2 to 15 percent of bladder length is placed onstaging reel 37 is provided, and preferably about 5 to 10 percent inexcess.

[0043] Referring now to FIG. 4, installation of resin impregnated liner33 using an improved pull in and inflate method in accordance with theinvention is illustrated. Resin impregnated liner 33 is pulled into thepipeline section 26 to be relined with about a foot of liner 39extending into upstream manhole U. A length of excess of liner 41 ofabout eight to ten feet remains in downstream manhole D. Excess 41 maybe held on surface 25 by a piece of tape or rope 42 secured to a sandbag43. Excess liner 41 is provided to accommodate movement of liner 33 asit is expanded.

[0044] In the conventional pull in and inflate installation processutilizing a water eversion process, pressure within the bladder andliner is maintained due to the height of the water column within thedowntube. Cure is initiated by exposing the impregnated liner to heat.This is usually accomplished by introducing heated water into theeversion pipe or by circulating hot water through a recirculation hosepulled into the everting bladder by a hold back rope connected to thetrailing end of the everting bladder. Generally, cure takes betweenabout 3 to 5 hours depending on the type of resin selected and thethickness of the liner. After cure, entry into the downstream manhole isnecessary to release the heated water after cure prior to removal of theinflation bladder.

[0045]FIG. 5 illustrates an eversion apparatus 44 including a downtube45 and an eversion elbow 46 used in accordance with a preferredembodiment of the invention. Eversion apparatus 44 is mounted oneasement unit 36 for convenience during the installation. An elevatingplatform 47 on easement unit 36 allows for easy adjustment of heightdepending on the depth of manhole U. Elbow 46 includes an inlet orvertical section 48 and an outlet or horizontal section 49. A lowerinlet gland or sphincter valve 51 with an air inlet 52 for pressurizinga flexible element within lower gland 51 is mounted to the inlet side ofvertical section 48. An upper gland 54 with an air inlet 56 is alsomounted to the inlet of downtube 45. Both upper gland 54 and lower gland51 are constructed similarly. Each is a spincter valve formed from aflexible element secured within an outer cylindrical wall so that achamber is formed behind the flexible wall to pressurize the flexibleelement against bladder 38. Each gland 51 and 54 is constructed andoperates similarly to the eversion apparatus described in U.S. Pat. No.5,154,936, the contents of which are incorporated herein by reference.

[0046] Inflation bladder 38 wound on staging reel 37 on easement unit 36is fed through downtube 45, upper gland 54, lower gland 51 and elbow 46.Bladder 38 is then cuffed back and banded to horizontal section 49 ofelbow 46. Upper gland 54 is pressurized against bladder 38 before theeversion begins in order to isolate bladder 38. Air pressure is appliedto air/steam inlet 61 and to bladder 38 sufficient to effect theeversion. Lubricant is applied to the surface of bladder 38 tofacilitate movement through upper gland 54 during the eversion ofbladder 38

[0047] Horizontal section 49 of elbow 46 is fitted with a flexiblestarter sleeve 58. Starter sleeve 58 is a length of about two feet offlexible robust tubular material banded over bladder 38 with at leastone banding strap 59. Starter sleeve 58 is sufficiently flexible so thatwhen not supported it will generally lay flat. When attached tohorizontal portion 49 of elbow 46, distal end of starter sleeve 58 liesflat as illustrated in FIG. 6. Eversion apparatus 44 is lowered intoupstream manhole U and the flattened end of starter sleeve 58 isinserted into the upstream end of liner 33 so that the liner overlapsstarter sleeve 58 by at least about 3 to 6 inches. Care is taken tomaintain starter sleeve 58 flat about the end of bladder 38 to avoidintroduction of air into liner 33. Alternatively, liner 33 can be simplysecured about bladder 38 by banding or the like.

[0048] Inflation bladder 38 is formed of a tube of thermoplastic film,such as a polyolefin or polyvinyl chloride. A wide variety ofthermoplastic materials would be suitable, such as polypropylene orpolyurethane so long as the material will withstand the temperaturesreached during cure.

[0049] Horizontal section 49 of elbow 46 is formed with an air/streaminlet port 61 for receiving air for eversion of bladder 38 and steam forcure. In the illustrated embodiment, elbow 46 also includes a condensatedrain 62 for removing any condensate that forms in bladder 38 duringcure and cool down. After inflation bladder 38 and starter sleeve 58 areinstalled, eversion assembly 44 is positioned in upstream manhole U asshown in FIG. 6.

[0050] At this time, inflation of liner 33 is ready to begin. At thestart, air at about 5 psi is introduced in to upper gland 54. Once airpressure has stabilized, inflation bladder 38 is lubricated andpermitted to proceed through eversion apparatus 44 while maintaining aneversion pressure of about 5 psi.

[0051] Inflation bladder 38 is everted through starter sleeve 58 byintroducing air into air/steam inlet port 61 of elbow 46. In thepreferred embodiment, air is introduced from an air inlet line 63 fedthrough a valve manifold 64 shown in FIG. 8. Air is then directed toair/steam inlet line 65. As inflation bladder 38 passes through startersleeve 58 and enters liner 33, starter sleeve 58 will be locked inagainst the inlet of pipeline section 26 thereby locking eversionapparatus 44 and elbow 46 in place in upstream manhole U. Inflationbladder 38 continues to evert through liner 33 until it is brought to afew feet from downstream manhole D.

[0052] The details of valve manifold 64 and the piping attached toeversion apparatus 44 is shown in FIG. 8. Air enters from air hose 63through an air pressure regulator 81 and pressure is controlled by anair valve 82. Steam entering from steam hose 77 is regulated by a steampressure regulator 83 and controlled by a steam valve 84. Air and steamare mixed in air/steam hose 65 after passing through air/steamtemperature gauge 79 and air/steam pressure gauge 78. Air/steam inlethose 65 is coupled to manifold 64 and air/steam inlet in elbow 46 by apair of cam lock fittings 86 or any other convenient hose coupling.

[0053] When the eversion continues and bladder 38 approaches downstreammanhole D, inflation bladder 38 is stopped at about 5 to 10 feet fromdownstream manhole D. The 5 psi air pressure is maintained when theeversion is stopped. At this time, the remaining excess of liner 33 indownstream manhole D is cut to about one foot from the back face ofdownstream manhole D. A sample mold 67 and two screw-type bands 66 areplaced over the end of liner 33. The distal end of liner 33 is thenbanded about a cylindrical receiving canister 68 positioned at the backof downstream manhole D. Liner 33 is then secured to canister 68 withbands 66.

[0054] Canister 68 is a cyclindrical section of rigid material having aclosed backwall 69. A bladder punch 71 is mounted to backwall 69.Bladder punch 71 is a sharp tapered tubular member coupled to acondensate drain 72 through backwall 69. An exhaust coupling 73 isfitted to condensate a drain 72 and an exhaust hose 74 is coupledthereto. The free end of exhaust hose 74 is positioned outside ofdownstream manhole D and securely positioned so that any steam-airdischarge will not cause a safety hazard. At this time, thermocouplesand pressure gauges at the steam-air discharge to read temperature andstream-air flow may be installed.

[0055] Receiving canister 68 is positioned securely within downstreammanhole D using sandbags or other convenient implements. At this time,eversion of bladder 38 is resumed at the 5 psi air pressure. Inflationbladder 38 is everted until the nose of bladder 38 reaches backwall 69of receiving canister 68. When bladder punch 71 punctures the evertingface of bladder 38 allowing air to exhaust through exhaust hose 74.Pressure in inflation bladder 38 can be controlled by an exhaust value76 on exhaust hose 74.

[0056] At this time air pressure between about 20 to 30 psi is appliedto lower gland 51 and steam is introduced into air/stream inlet port 61to initiate cure of the resin in liner 33. Steam is provided from asteam inlet hose 77 which is regulated by valve manifold 64 to providean air/steam mixture to air/steam inlet line 65 for providing steam toeversion elbow 46. The air/steam flow is adjusted to maintain a curingpressure of about 7-10 psi until the combined air/steam flowtemperatures reach a desired temperature of about 220° F. measured atexhaust hose 74. Depending upon the particular resin and tube thickness,once the cure is complete, steam flow is turned off while simultaneouslyadjusting the air flow to maintain cure pressured. Exhaust valve 76 isadjusted while cooling to about 150° F.

[0057] Once the temperature has cooled to the desired level, air flowpressure is reduced to zero, exhaust valve 76 is fully opened andinflation bladder 38 is slowly de-everted. As bladder 38 de-everts, itwill seal off the punctured end. Accordingly, it is desirable to monitorthe air flow pressure to prevent pressure build up. Any condensate thatmay have accumulated in bladder 38 is removed by condensate drain 62 inelbow 46.

[0058] In the alternative embodiment illustrated in FIG. 10, a flexiblereceiving sleeve 87 is secured to canister 68 by a pair of bands 66.Receiving sleeve 87 is of the same robust flexible material as startersleeve 58 and operates in the same manner to seal expanding liner 33positioned therein between everting bladder 38 and the insider ofreceiving sleeve 87. As bladder 38 approaches backwall 69 and ispunctured, pressure is maintained within bladder 38 in the same manneras described in connection with FIG. 9.

[0059] After bladder 38 has been totally de-everted, it is safe to enterdownstream manhole D and remove sample mold 67 and receiving canister68. Eversion apparatus 44 is then removed from upstream U and any curedliner extending into either manhole is trimmed. At this time, liner 33is now ready for any lateral reinstatement.

[0060] It can readily be seen that the process in accordance with theinvention readily allows one to attain the advantage of curing a resinliner with flow through steam. By practicing the process, a tubularmember can be easily everted through an existing pipeline. By clampingand then cutting an opening in the distal end of the everted tubularmember, pressure can be maintained within the everting tubular memberand steam can be introduced at the eversion access and flow through thecuring liner to utilize the higher energy available in the steam to curethe resin significantly faster than one can cure utilizing circulatinghot water.

[0061] It will thus be seen that the objects set fort above, among thosemade apparent from the preceding description, are efficiently attainedand, since certain changes may be made and carrying out the above methodand in the construction set forth without departing from the spirit andscope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

[0062] It is also to be understood that the following claims areintended to cover all of the generic and specific features of theinvention herein described and all statements of the scope of theinvention which, as a matter of language, might be said to fall therebetween.

What is claimed is:
 1. A method for trenchless rehabilitation of anexisting pipeline by pulling a flexible resin impregnated liner into theexisting pipeline from a first access opening to a second access openingand everting a flexible inflation bladder from an eversion access intothe pulled in liner to a receiving access to conform the liner to theexisting pipeline and curing the resin in the liner, comprising:providing a supply of flexible resin impregnated liner and pulling theleading end of the flexible liner into the pipeline from one of theaccess openings to the other access opening with the ends of the linerextending beyond the ends of the pipeline into the access openings;providing a supply of flexible inflation bladder and feeding theinflation bladder into the proximal end of the liner in the eversionaccess; sealingly engaging the inflation bladder in the eversion accessto isolate the interior of the inflation bladder; introducing air intothe bladder in the eversion access downstream of the sealing engagementof the bladder to force the bladder into the interior of the flexibleliner; controlling the speed of eversion of the bladder into the linerby the rate of introduction of air and tension maintained on the bladderuntil the everting bladder extends to the opposite end of the liner;forming an opening in the bladder in the receiving access whilemaintaining pressure in the interior of the bladder and allowing air toflow-through the bladder and exit the receiving access; introducingsteam into the interior of the bladder at the eversion access downstreamfrom the seal on the bladder and allowing the steam to flow through thebladder and exit through the bladder opening; and allowing the resin inthe liner to cure.
 2. The method for trenchless rehabilitation of claim1, including providing the supply of flexible inflation bladder wound ona staging spool positioned at the eversion access.
 3. The method fortrenchless rehabilitation of claim 1, including sealingly engaging theinflation bladder at the eversion access by pressurizing at least oneselectively closeable gland about the bladder.
 4. The method fortrenchless rehabilitation of claim 4, including the step of feeding thebladder into a cylindrical member at the receiving access to retrainexpansion of the bladder.
 5. The method for trenchless rehabilitation ofclaim 4, including puncturing the bladder in the cylindrical member. 6.The method for trenchless rehabilitation of claim 1, wherein forming theopening in the bladder includes the step of everting the bladder into acylindrical receiving canister which forms a seal between the receivingcanister and the bladder and forming an opening in the bladderdownstream of the seal to allow for flow-through through the bladder. 7.The method for trenchless rehabilitation of claim 1, including forming aseal at the receiving access by banding the distal end of the linerabout a receiving canister and everting the bladder in the canister. 8.The method for trenchless rehabilitation of claim 1, includingintroducing steam into the bladder by mixing the steam with air prior tointroduction into the interior of the bladder.
 9. The method fortrenchless rehabilitation of claim 1, including applying a greaterpressure to the inflation bladder to sealingly engage the bladder thanthe air pressure introduce to evert the bladder.
 10. The method fortrenchless rehabilitation of claim 1, wherein the step of feeding thebladder through a flexible starter sleeve and placing the starter sleeveinto the liner into the proximal end of the liner.
 11. The method fortrenchless rehabilitation of claim 6, including everting the inflationbladder into tubular member and clamping the distal end of the inflationbladder everted through the tubular member.
 12. The method fortrenchless rehabilitation of claim 1, wherein the flexible inflationbladder is an impermeable thermoplastic film.
 13. The method fortrenchless rehabilitation of claim 1, wherein the inflation bladder is apolypropylene film.
 14. The method for trenchless rehabilitation ofclaim 1, wherein the inflation bladder is a thin thermoplastic filmhaving a layer of impregnable material on the interior surface.
 15. Aneversion apparatus for use in the installation of a flexible cured inplace liner in an existing pipeline, comprising: a tubular member havingan inlet opening and an outlet opening; a selectively actuable clamp forreceiving an inflation bladder to form a seal about the bladder and toallow the bladder to pass therethrough, the clamp mounted at the inletopening; and the outlet opening adapted to secure the bladder theretoand sealingly engage the collapsed liner; whereby the assembled eversionapparatus and bladder can be positioned at one end of the liner foreversion of the bladder to inflate the liner.
 16. The eversion apparatusof claim 15, wherein the clamp is selectively actuable by fluidpressure.
 17. The eversion apparatus of claim 15, wherein the claim is asphincter valve.
 18. The eversion apparatus of claim 15, wherein thetubular member includes an elbow with the sphincter valve mounted at theinlet to the tubular member.
 19. The eversion apparatus of claim 15,further including a tubular downtube for receiving the inflation bladdermounted to the inlet side of the sphincter.
 20. The eversion apparatusof claim 17, further including a downtube mounted on the inlet side ofthe sphincter valve.
 21. The eversion apparatus of claim 20, furtherincluding an upper clamp valve mounted to the inlet to the downtube. 22.The eversion apparatus of claim 20, further including an upper sphinctervalve mounted to the inlet of the downtube.
 23. The eversion apparatusof claim 15, wherein the tubular member is an elbow.
 24. The eversionapparatus of claim 23, wherein the elbow is substantially rigid.
 25. Theeversion apparatus of claim 24, wherein the elbow includes an air/steaminlet.
 26. A receiving canister for use in trenchless rehabilitation ofan existing pipeline, comprising; a substantially cylindrical member forrestraining for restraining an everting bladder for receiving theeverting inflation bladder and forming a seal between the exterior ofthe bladder and the interior of the canister and having a backwall atthe distal end of the canister; a bladder punch disposed in the backwallof the canister for forming an opening in the everting bladder; and anexhaust connection in communication with the interior of the receivingcanister downstream of the face of the everting bladder to provideflow-through from the interior of the bladder.
 27. The receivingcanister of claim 26, wherein the tubular portion is substantiallyrigid.
 28. The receiving canister of claim 26, further including acondensate drain for removal of the condensate from the canister.
 29. Aneasement unit for trenchless rehabilitation of an existing pipeline byinserting a flexible resin impregnated liner in to an existing pipelineand everting an inflation bladder within the inserted liner to conformthe liner to the existing pipeline, comprising: a displaceable frame; asupply spool of an endless length flexible inflation bladder disposed onthe frame; and a bladder staging reel disposed on the frame forreceiving a length of inflation bladder in a length at least equal tothe length of the portion of the pipeline to be repaired from the supplyspool for feeding into the liner.
 30. A method for trenchlessrehabilitation of an existing pipeline by pulling a flexible resinimpregnated liner into the existing pipeline from a first access openingto a second access opening and everting a flexible inflation bladderfrom an eversion access into the pulled in liner to a receiving accessto conform the liner to the existing pipeline and curing the resin inthe liner, comprising: providing a supply of flexible resin impregnatedliner and pulling the leading end of the flexible liner into thepipeline from one of the access openings to the other access openingwith the ends of the liner extending beyond the ends of the pipelineinto the access openings; providing a supply of flexible inflationbladder and feeding the inflation bladder into the proximal end of theliner in the eversion access; sealingly engaging the inflation bladderin the eversion access to isolate the interior of the inflation bladder;introducing air into the bladder in the eversion access downstream ofthe sealing engagement of the bladder to force the bladder into theinterior of the flexible liner; controlling the speed of eversion of thebladder into the liner by the rate of introduction of air and tensionmaintained on the bladder until the everting bladder extends to theopposite end of the liner; clamping the bladder in the receiving accesswhile maintaining pressure in the interior of the bladder; cutting thedistal end of the everted bladder and allowing air to flow-through thebladder and exit the receiving access; introducing steam into theinterior of the bladder at the eversion access downstream from the sealon the bladder and allowing the steam to flow through the bladder andexit through the bladder opening; and allowing the resin in the liner tocure.
 31. A method for trenchless rehabilitation of an existing pipelineby pulling a flexible resin impregnated liner into the existing pipelinefrom a first access opening to a second access opening and everting aflexible inflation bladder from an eversion access into the pulled inliner to a receiving access to conform the liner to the existingpipeline and curing the resin in the liner, comprising: providing asupply of flexible resin impregnated liner and pulling the leading endof the flexible liner into the pipeline from one of the access openingsto the other access opening with the ends of the liner extending beyondthe ends of the pipeline into the access openings; providing a supply offlexible inflation bladder and feeding the inflation bladder into theproximal end of the liner in the eversion access; sealingly engaging theinflation bladder in the eversion access to isolate the interior of theinflation bladder; introducing air into the bladder in the eversionaccess downstream of the sealing engagement of the bladder to force thebladder into the interior of the flexible liner; everting the bladderthrough the liner until the everting bladder extends to the opposite endof the liner; clamping the distal end of the bladder and forming anopening in the bladder while maintaining pressure in the interior of thebladder and allowing air to flow-through the bladder and exit thereceiving access; introducing steam into the interior of the bladderdownstream from the seal on the bladder and allowing the steam to flowthrough the bladder and exit through the bladder opening; and allowingthe resin in the liner to cure.
 32. The method for trenchlessrehabilitation of claim 31, including everting the bladder through aflexible tubular member at the receiving access; clamping the flexibletubular member and bladder at the receiving access to maintain pressurein the bladder; cutting the distal end of the tubular member andbladder; and attaching the cut tubular member and bladder to a valve topermit flow-through the bladder without loss of pressure therein.
 33. Inmethod for trenchless rehabilitation of an existing pipeline with aresin impregnated liner from a first access opening to a second accessopening by everting a flexible tubular member from one access into theexisting pipeline and curing the resin, the improvement which comprises:providing a supply of flexible tubular member and sealingly engaging thetubular member in the access to isolate the interior of the tubularmember; end of the flexible liner into the pipeline from one of theaccess openings to the other access opening with the ends of the linerextending beyond the ends of the pipeline into the access openings;providing a supply of flexible inflation bladder and feeding theinflation bladder into the proximal end of the liner in the eversionaccess; introducing air into the tubular member downstream of thesealing engagement into the interior of the tubular member; everting thetubular member through existing pipeline; clamping the distal end of thetubular member and forming an opening thereon while maintaining pressurein the interior and allowing air to flow-through the tubular member;introducing steam into the interior of the tubular member downstreamfrom the seal on the tubular member and allowing the steam to flowthere-through and exit through the opening in the tubular member; andallowing the resin to cure.